Galería de casos
Caso 1
[twenty20 img1="75" img2="76" offset="0.5" before="Antes" after="Después"]
Caso 4
[twenty20 img1="81" img2="82" offset="0.5" before="Antes" after="Después"]
Caso 2
[twenty20 img1="77" img2="78" offset="0.5" before="Antes" after="Después"]
Caso 5
[twenty20 img1="83" img2="84" offset="0.5" before="Antes" after="Después"]
Caso 3
[twenty20 img1="79" img2="80" offset="0.5" before="Antes" after="Después"]
Caso 6
[twenty20 img1="57" img2="58" offset="0.5" before="Antes" after="Después"]